Nonstop Database, HiRDB Version 9 System Operation Guide

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26.6.3 Grouped system switchover

This subsection describes the methods of performing a grouped system switchover when you are using HA Monitor as your cluster software. To perform a grouped system switchover when using a cluster software product other than HA Monitor, see the documentation for that cluster software product.

Organization of this subsection
(1) Monitor mode
(2) Grouped system switchovers with HiRDB Datareplicator
(3) Relationship to planned system switchovers

(1) Monitor mode

The following explanation assumes a grouped system switchover configuration set up in HiRDB and OpenTP1.

To perform a grouped system switchover, use the group operand and termcommand operand of HA Monitor to define a grouped system switchover configuration. For details about how to define a grouped system switchover configuration, see the manual High-Availability System Monitoring Facility. The following table lists system processing when a grouped system switchover is performed (in the monitor mode).

Table 26-31 System processing when a grouped system switchover is performed (in the monitor mode)

Error description System processing
An error occurred that prevents hardware from restarting, or an error occurred when the operating system or HA Monitor was restarting (a system failure occurred). Performs a system switchover. Also performs switchovers for OpenTP1 and HiRDB.
An error occurred in OpenTP1 and OpenTP1 terminated abnormally (OpenTP1 must be in the server mode). Performs a system switchover. When a system switchover is performed in OpenTP1, a grouped system switchover is also performed in HiRDB.
An error occurred in HiRDB and HiRDB terminated abnormally. Does not perform a system switchover. Restarts HiRDB on the running system.

(2) Grouped system switchovers with HiRDB Datareplicator

If you are using HiRDB Datareplicator, you must perform grouped system switchovers with both HiRDB and HiRDB Datareplicator. In such a case, use the group operand of HA Monitor to define HiRDB and HiRDB Datareplicator in the same server group. For details about how to define a grouped system switchover configuration, see the manual High-Availability System Monitoring Facility. For details about the operations involved in performing a system switchover when using HiRDB Datareplicator, see the HiRDB Datareplicator Version 8 Description, User's Guide and Operator's Guide.

Conditions
In the termcommand operand of HA Monitor, you must specify a command or shell that forcibly terminates HiRDB Datareplicator.

Automatic system switchovers
When an error occurs on the running system, the system switches automatically to the standby system. No action needs to be taken by the HiRDB administrator or HiRDB Datareplicator administrator.

Planned system switchovers
You can use HA Monitor's monswap command to perform a planned system switchover in HiRDB and HiRDB Datareplicator.

When an error occurs in HiRDB Datareplicator
If HiRDB Datareplicator independently terminates abnormally, a system switchover is not performed because HiRDB Datareplicator restarts on the running system. Note that, if HiRDB Datareplicator independently terminates abnormally, a grouped system switchover cannot be performed on either HiRDB or HiRDB Datareplicator.

(3) Relationship to planned system switchovers

If you define a grouped system switchover configuration in advance, you can use the planned system switchover functionality of HA Monitor's monswap command to perform grouped system switchovers.